Report of the Keiv Committee. 



155 



This having been reported to the Meteorological Council, it was 

 decided by them to request Professor J. J. Thomson to examine into 

 the subject of the measurement of Atmospheric Electricity, and, 

 meanwhile, to continue the instrument in action in its present 

 condition. 



III. Solar Observations. 



Sun-spots. — Sketches of Sun-spots have been made on 170 days, and 

 the groups numbered after Schwabe's method. 



Time Signals. — These have been received from Greenwich through 

 the G.P.O. with regularity since last report, with the following ex- 

 ceptions : — 



On six occasions, viz., March 10; May 30 ; August 18, 19, and 27 ; 

 and September 11, no signal was received either at 10 A.M. or 

 1 P.M. On January 14 and February 4 it arrived two seconds late, 

 and on October 8, 9, and 10 it did not record itself on the chrono- 

 graph, but was only observed by the galvanometer. 



Transit Observation. — Occasional solar and sidereal transits have 

 been observed as checks upon the Greenwich signalled times. 



Violle's Actinometer. — The copies of the observations made during 

 1890 were duly forwarded to the Meteorological Office in January, 

 and, as the Committee understand, have been handed over by that 

 Office to Mr. H. !F. Blanford, who will report on the subject to the 

 Solar Physics Committee. 



IV. Experimental Work. 



The Committee have had under trial on the roof of the Observatory 

 two new forms of wind registering instruments, the anemo-cinemo- 

 graph of MM. Richard Ereres, of Paris, and the sight-indicating 

 velocity meter by Munro, of London. 



The first- named instrument is an improved form of the old wind- 

 mill vanes anemometer which was used by Smeaton after House and 

 Eobins, but is best known as WhewelPs. The anemo-cinemograph is 

 similar to that which was employed on the top of the Eiffel Tower at 

 Paris, and the vanes, by running constantly against a train of clock- 

 work, record directly on a sheet of paper the velocity of motion of the 

 wind at any time. Continuous records were obtained for six months, 

 and the result given would seem to show that the indications of the 

 Kew Beckley anemograph are in excess of those given by the new 

 instrument. These are 20 per cent, less than those of the anemo- 

 graph with winds blowing at 40 miles or upwards per hour, and 

 12 per cent, less with light winds which blow at from 6 to 10 miles 



